Remote-control telephone system



June 24, 1930. w. T. POWELL 1,766,402

REMOTE CONTROL TELEPHONE SYSTEM Filed Oct. 16, 1929 2 Sheets-She et 1 2e PEN 2? Am" 0 .P (5

LANE. ,EIW 1 TCH IVNVENTO'R W/NFEED 7. POWELL.

PARTY TELEPHONE NE.

ATTORNEY June 24, 1930.

w. POWELL REIOTE CONTROL TELEPHONE SYSTEM Filed 001;. 16, 1929 2 Sheets-Sheet 2 INVENTOR WINFEED 7. Powsu.

Patented June 24, 1930 i CAR-LSON TELEPHONE iunnoraorun ne f CORPORATION OF NEW.YORK

MP N F H WEB, (N W YQ K,

nnnorn-coivrnon TnL-nrnonE-sizsrniu Application filedflctober 15,

I This invention relates to telephone systems and more-p artioularly totelephone systems in l\VlliCll automatic switches under icontrol of subscribersand operators are employed to complete telephoneconnections. It frequently happens that a small group of rural telephone subscribers are localized: in a-community which is rather remote to the 1 telephone exchange. In such communities -10 the subscribers outside telephone lines are so poorly constructed that it is impossible to direotively control automatic switches thereover. In addition the subscribers substation equipment is of the local battery type in which ahand-operatedgenerator signals 1 the initiationand termination of a call. The rates in such communities are so low that they a do not justify the replacement of the substation equipment and the rebuilding of the outside telephone lines 'sothat impulse senders or dials and directively operated automatic switches may be employed to establish telephone-connections; Furthermore, such communities are frequently so small that they 125 do not justify the services ofa telephone operator sothat these subscribers are new tally served from a remotewteleplione exchange. The use of such aremote telephone 1 exchange requires the use of long subscribers: 0 lines whichare expensive to maintain and are inefficient in service.

In my co-pending application 3e8 TO9 filed. r Ell larch 1, 1929 there is described a system in p which-telephone lines of a group. ofilocal battery subscribers in aciszmal'l community may be connected tov a remote. eiicliangewhcre an-operator provided with .an impulse SQllClBFIfi .may operate automatic switches :of asimple j type to extend a calling line totheqlineot a i wanted subscriber. In thisnsystemitJisalso arrangedso that a subscriberzon ia partywline may signal another subscriberthereon byw Lineans of code ringing without-the interven-. u tionof an operator. a :The; present inventionirelates to an improvement over the previously mentioned: system which incorporates means: t'orreleas ingthe connection under thecontrol otthe callingsubscriber by merelyfreplacinglhisi receiver on the switchhook without the need 1929., Serial nopssases.

v oftransmitting arelease signal trom his magneto generator. In the previously mentioned application the system was, also arranged to release-the connection after aspredetermined time period while in the present disclosure the release of the connection is efiected by the callingjsubscriber independently of any time interval- In addition the present disclosurc comprises system which has been simplified over-the previously mentioned system and which provides amore efiicient method or operation.

I In. the drawings 1 Fig. l 1 1 diagrammatically representsa portion of a telephone system including a calling telephone line and its lineswitch circuit equipment, a, common bridge or connecting circuit and a called telephone line, the hne switch circuit otwhich has been omittedsinee it is identicalwith that shown in connection-With the. calling l1ne; ;F1g. 2 represents common controlequipment including a registersender and, a finder sw tch for associatmg antldlev register, sender with a bridgecircuihtaken for use;.at the right of the broken. line ofFig-Qthere is indicatedan operatonsposition and a portion of the telephone equipment associated there with whereby an operatonmay.receive-the designation ofa wantedisubsoriber over. a calling line and operate, the v selected registeri sender to eil'ect a: telephone connection between acalling telephone line and the line of a wantedsuhscriber. i

when the subscriber atisubstation A desires to infitiatevacalhhe operates the magnetogenerator l located thereat-wlhich transmits ringing current through the contactQ of thetgenerator overthe upper.sidecithe.subscribers line, Winding :of theialternating; current relay 5,1 lower back contact. :and armature of relayfi thence over thei-lowertside, of the subsclllbvefisline to the other terminalrof the magneto The relay. his thus energized; and at its armature and contact-completes an .operatingicircuit torbthe slow-releasingrelay 7. This last-namedrelay closes a break point in thedrivingcircuit ofthe motor magnet 8 of the line switclntraceable from grounded bat- .ter'y -resistancei 9,: Winding, back, contact :and

armature of this magnet, upper front contact and armature of relay 7, inner back contact and armature of relay 6 to ground. In the event that the brushes of the line switch have been standing in engagement with the terminals of a busy bridge, this circuit is effective to advance these brushes until the terminals of an idle bridge is found. During the time that the line switch is operating a circuit is extended from grounded battery, resistance 9, lower contact and armature of relay 7, low

resistance winding of relay 6, armature and upper contact of relay 13, to the outgoing test brush 14. This circuit however is not completed until an idle bridge is found at which time'the circuit is closed through the test terminal 40, and conductor of the bridge, control switch brush 10 in position 1 to ground. On the completion of this circuit the relay 6 is energized to stop the operation of the line switch and also to close its armatures and front contacts which extend the calling line through the line switch brushes 16 and 17 and through both windings of the relay 11 in series to ground and grounded battery respectively. This operates the relay 11 which in turn effects the energization of the slow releasing relay 12. The relay 12 then closes a locking circuit for the switching relay 6 from ground, its upper armature and front contact and high resistance winding, outgoing test brush 14, front contact and armature of relay 12, resistance, to grounded battery. The operation of the relay 12 also advances the control switch into position 2 by the closure of a circuit from grounded battery, winding of its motor magnet 18, its back contact and armature, control switch brush 20 in position 1, upper front contact and armature of slow releasing relay 12 to ground.

, As soon as the control switch reaches position 2 an idle finder switch is started to associate an idle register sender with the bridge circuit taken for use. This is effected over a circuit completed from grounded battery, winding of the motor magnet 18, its back contact and armature, brush 20 in position 2, conductor 21, brush 22 in position 1, winding of the slow releasing relay 23 to ground. The relay 23 is thus energized and completes an operating circuit for the mo-tor magnet 24 of the finder from grounded battery, resistance unit, winding of the motor magnet 24, its back contact and armature, arma ture and front contact of relay 23, back contact and armature of relay 25 to ground. Under the control of this circuit the motor magnet 24 advances the brushes of its finder switch until its test brush 26 encounters the test terminal 27 leading to the bridge circuit taken for use which is assumed to be that shown in Fig. 1. As soon as this test brush engages the terminal 27, an energizing circuit for relay 25 is completed from grounded battery, resistance unit, left hand armature and contact of relay 23, left hand winding of relay 25, brush 26, terminal 27 conductor 28, control switch brush 10 in position 2 to ground. This circuit is also eifective to shunt the motor magnet 24 and thereby stop the operation of the finder switch. As soon as the relay 25 operates, it closes a circuit from ground, its inner armature and contact, brush 22 in position 1, conductor 21, control switch brush 20 in position 2, back contact, armature and winding of magnet 18 to grounded battery, which circuit is effective to advance the control switch from position 2 to position 3. In this position a locking circuit for the switching relay 25 is closed from ground, its right hand armature, front contact and its high resistance winding, brush 26, terminal 27, conductor 28, back contact and armature of relay 29, control brush 30 in position 3 to grounded battery. Also, as soon as the switching relay 25 operated, it actuated the relay 31 from grounded battery, winding of this relay, outer front contact and armature of relay 25 to ground. The energization of this last named relay closes an operating circuit for the units register motor magnet 32 extending from battery, winding, back contact and armature of this magnet, units register brush 33 in position 1, inner, lower front contact and armature of relay 31, back contacts and armatures of slow releasing relay 34 and the impulse relay 35, to ground. Under the control of this circuit the motor magnet 32 advances the units register brushes into position 3 where its brush 36 closes a circuit from ground, tens register brush 37 in position 1, armature,back contact and winding of the motor magnet 38 of the tens register to grounded battery. This circuit causes the motor magnet to advance the brushes ofthe tens register into position 4.

In positions 2 and 3 of the control switch brush 39, battery potential is applied to the outgoing test terminal 40 of the calling line switch for maintaining the locking circuit of the line switch. Ringing current from the calling subscribers generator may now be transmitted over the two sides of the subscribers line in series through the condensers 44 and 45, conductors 46 and 47 to the winding of the drop 48, conductor 46 being extended through the upper, back contact and armature of relay 49, conductor 50, finder brush 51, tens register brush 52 in position 4, normally closed contacts of the jack J to one end of the winding of the drop 48, the conductor 47 being extended through finder brush 53, tens register brush 54 in position 4, normally closed contacts of the jack to the other end of the winding of the drop 48. The drop 48 is thus actuated and serves as a signal to the operator to insert the plug P of her listening equipment into the jack J leading to the bridge and calling line of Fig. 1. The operator also has a listening key LK to connect her'listening equipment to the cord circuit turel'and front contact of relay '34:, armature);

jack J'a circuitis completed from grounded;

through both windings of the impedance coil r 56 in multiple, over the two sides of the oper ator s cordYcircuit through the tip and ring contacts of plug P and'jack "J' and thence through both windings of the impulse ,relay multiple to ground). This energizes the erating' circuit through the slow releasing relay 34. i i

If the call just initiated is a revertive call, the bridge control switch remains i11'-po= ,'ition 3 until the operator Whose equipmentis shown at the right of Fig. 2 inserts the plug J and then subsequentlyWithdraws it, which In positio "4 of'theunits register the units 5 operation is first eflective to energ i zethe inn pulse relay 35 and the slow releasing relay,

to advance the tens register into position 5 iii a circuit closed from ground at the armature and baokcontactof relay 35,

and'fcontact of relay ll winding of the tens; motor magnet 38 to grounded loatteryf When the relay34 releases on the withdrawal v,

plug]? from jack J, this tens register is tidvancedfito position 22, from ground at the a rmaturesand back contacts of relays 35 and "I 34, tens1register brush 37 closed in positions from' o to 21, armature, baolrcontacft' and windifngof the motor magnet 38 to grounded hattery. The unit srregister is advanced to position 22 through tens brush 42 in position 22, units freg'ister brush 43,1 armature baok COnfifE iCh and Winding of I the motor magnet I 32 to grounded battery and in this positio'n stored "to normal. j 7

Let it be assumed that the call is not revertiiie but for anotherline hayingfas its des; ignati'on lH inw'hich the numeral 4 cor 0'13 the units regfister,f the tens; register is 'rerespondsfto the subs oribers station Jon the calledpartyiline It willbe recalled that the controljswitch of the bridge is inj'posi; tionlS, thetensregister is in position t and the units register is in position 3. The open' l 4 o I A ator now actuates the dial mpulse springs Ito transmit one impulse corresponding to #1; the lmpulse relay 35deenerg1zes once and then remains energ zed. The deenergi z ati'on of this relay closes'j'a circuit from ground, armature and back contact out relay 35,1 frontyconta'ct and armature ofrelay 34, armature, front contact and right hand Winch ingfof change-overrelay 41 to grounded loatstory} The motorinagnet 38 ofthe tens reg ister is operated in multiple ofjthi's last de-I" scribed circuit from grounded'hattery, Windmg of the motor magnet 38, front con tact and"arn1ature0f rel g'ty 41 and thence to groju d. at ithe armature and back contact of 3 an e-e re ay" .7 e ii d ru. {The motor magnet 32 of the unlts reg ster is leasl' g 'it remaias impulse'telay 35 as s riou ly.de rees aen'efitfheia operated during a series 015 ini'phl'ses; moto tens irn pu lse lias jlie en transmitted, the/Hm,

tens register to jadi ance to' position 5 corre-' e 1#' j it the tie-ee '1 of this Series i p ls the y;asre neinsj" p'ulse 'relay 35 which in tu n H t MiQP- f whiell len es the changeiver r918) 9'0 bleenergize aiid adVance the u'nits'reg i ste r into armature and back contact of chaiige ovor relaji ruining re 'iste'r brush 33 in position 3'. armature, back contact and WllidlIlQJQf! P of her telephone equipment into the jack fr ffi g 2 gr ll batt ry.

change-oilerfrelay 57 is energized from groundfunits register brush 36, left' handf The unitsregmter 1s now 1n condition to transmission oiteach impulse th e impulse re- 9 lay 35 deenergizes and at its armature and back contact closes a'c rcuit from ground,

through wafer-meme and front contact of! I I, 4 7 1 1 slow releasr g relay 84,conductor58, armature, fr-on cont actland r ght 'hand 'wlndlng Winding heartened andarm'ature of relayt57and thence 'oi 'erithe reniaindefof the i1 cire'uit ously' descrihed to' groinid' at l n W armature "and haclt contact of the lmpulse' f Since the chane'e-over relay 57 7 1s slow reseries' of impulses. "Howeirer, t'h e ffiriotor clos} circuit to advancefthe co'ntfoliswitoh of E1 '1 from positioii ii to posit on 4'overa circhit effective froiii qround, un'itsjbru'sh '36 of motor ofjthepcdntrol switch to At this timetheslowf re- I s energ zedfrom grounded j grounded hatt leasing jrelay e brush 10 in position" l, to ground.

The operator now dialsthe digit #4:

battery, its lower winding; control switch e and Back 'cont ahtpf't go refere d throughout thi m v c it Q p l tflimc ge-o ver rel 13157 dee'n'ergi'zesiand thereby which is effective to cause the impult-ie relay i351 35 to deenergize four times after which it holds its armature actuated for a relatively long interval. On each retraction of the armature of this relay, a circuit is closed from ground, its armature and back contact, armature and front contact of relay 34, conductor 58, uppermost armature and contact of relay 31, tens register brush 54 in position 5, finder brush 58, conductor 63, inner armature and front contact of relay 64, winding of the motor magnet 18 of the control switch, to grounded battery. The slow releasing relay 64 is held energized during this series of impulses from grounded battery, its upper winding, front contact and armature and thence to ground at the armature and back contact of the impulse relay 35 as previously described. In response to each of the four station code impulses the magnet 18 advances the control switch until at the close of this series of impulses this switch is standing in position 8.

Referring back to the point where the units register brush 36 is advanced to position 6, a circuit is closed for operating the slow releasing busy relay 65 from grounded battery, its lowerwinding, back contact and armature of relay 66, back contact and armature of relay'67, units register brush 86, to ground.

The system is now in readiness to start the line switch of the called line to search for the other end of the bridge to which the calling line is connected. This operation is started over a circuit traceable from ground, control switch brush 68 in position 8, armature and back contact of relays 64 and 49, conductor 50, finder brush 51, tens register brush 52 in position 5, armature and front contact of relay 65, winding of the test relay 69, its continuity spring and back contact and through similar springs and contacts of the series of test relays such as and 71, thence through the back contacts and continuity springs of relay 7 O, 71 and 69 to the battery through the resistance coil 72. This circuit operates the relay 69 but it willbe understood that the wiring and continuity contacts of relays .69, 70 and 71 is such that only one of these test relays is operated at any one time which is for the purpose of preventing the starting of more than one called line switch at any definite time. lVhen the relay 69 is energized, it closes a circuit for operating the relay 67 and it also closes a circuit from grounded battery, upper winding of the busy relay 65, front contact and armature of relay 69, tens register brush 73 in position 5, conductor 74, innermost contact and armature of the common #2 units relay designated 75,

conductor 76 which is the test wire indi-.

vidual to the line switch of line #12. This conductor then includes the winding of a relay, similar to 13 such as that shown in the line switch of Fig. 1 which is connected to ground through the back contacts and armature of relays similar to relays 7 and 6. The

armature and one of itscontacts, closes a lockinc' circuit for itself including the test conductor 76. The operation of the relay 13.

renders the terminating test brush 78 effective instead of the outgoing test brush 14. The operation of the line switch of the called line issimilar to the operation of the line switch of the calling line previously described except that the test brush similar to 78 is effective instead of the test brush similar to 14. 7

At this time a circuit is effective from the ground at the units register brush 36 at position 6, armature and front contact of relay 67, back contact and continuity spring of relay 66, winding of relay 66, to grounded battery. This last named relay is energized and closes a locking circuit for itself through its continuity spring and armature to ground at the register brush 36. A circuit is also completed from ground at the units register brush 36, front contact and armature of relay 67, conductor 79, tens register brush 54, finder brush 3, armature and back contact of relay 64, winding of the relay 80, control switch brush 39 in position 8 to grounded battcry. This circuit energizes the relay 80 and applies a stopping potential on the terminating test terminal 81 of thecalled line switch over a circuit in multiple of that just described, thence through the inner armature and front contact of relay 80, inner armature and back contact of ringing relay 49 to the test terminal 81. Potential on this terminalis effective to stop the called line switch in engagement with the selected bridge circuit which is assumed to be that shown in Fig. 1 at which time the cut-oif relay similar to 6 energizes to stop the operation of the motor magnetof this switch and to conn ct the called line conductors to the selected bridge circuit. The cutoff relay of the called line switch similar to relay 6 of Fig. 1, is locked from ground through its upper armati'ire and front contact, its high resistance winding, outgoing test brush 62, winding of the relay 49, front contact and armature of relay 12, thence to grounded battery, through the resistance coil. Relay 49 when thus energized disconnects the terminating'test terminal 81 so that there is no danger of another line switch seizing this bridge circuit at this point. The operation of the relay 49 also in errupts the circuit to ground at control switch brush 68 which was holdingthe ifielay..69 energized so that this. .toi1e device 91, .the .circuitextending troni relay .releases and closes a circuit: g-fIOIll ground; its lower. armature and back contact,

armature andiront-contact of relay 67, re-,

sistance coil 7 2 to grounded battery. Thisis effective to prevent the operation of aiiyotlier;

relay. similar to .69 untilthe relay -,6,7 is released.

Since the, controller switch is now i1i-posi-. tion 8 the code ringing c rcuitcorresponding.

to thezfmf-d station on the calledline is now connected by wayof the brush 84, back contact .ot the relay. 80, line switch brusli over.

thelower side of the called line. to the cons denser and ringer. 86 of the ,wanted station on the, calledline, called line switch brush, 87, conductor d6, armature and back contact-of relay 6-1,, brush 68,.to ground. The relay 80 is maintained energized. to prevent applying this. code ringing to the .calledline at any;.

time except the starto'f the code signalsince relay 80 is maintained energized as longas relay 67 is held operated and this last named relay is locked operatedthrough ts lower winding, frontcontact and armature,contact.

lioldiiigcircuit of the relay 80.- When relay At the. close oi the code ringing period Contact 88 of this interrupter is opened which allows... relay67-to deenergize ,aiidthereby open the.

position .to ground.

ground, condenser 92, backcontactand arnia- .tureot relayoi brusli 77 in positionlff, c0n-. ductor .94- to vthe/tip side of .theioperating trunk. andQthiiough the tip. contacts of the .jackJ and plug P to the operator.s listening" equipment.. The operator is instructed.

not to remove the plug D from the jack 5 untilv the release tone is heard. In this way the connection is maintained during a coni- .pletecode cycle when. it is once started. On

hearing the release tone the operator removesv the plug from the jack J to eiiect the .re-

lease of relays 34 and which advances the tens register to position 22 in acircuit (30311 .pleted from ground through lhe ainiatures and back contacts of relays35 and 3 i, brush tactv andwindingot niotor magnet- 38 to grounded battery. Followiiigthis operation the units register is moved to position 22 in .a circuit. extendingiroin grounded battery,

:tery,winding. ofits motor iiiagnetx38, its

back contact andarinature, units brush l3 in .37 in positions 5 to 21, arniatu e, hack con;

tens brush 42 in its position 22 in position 22 of the units regis. ter a c rcuit is closed. from ground at brush v.36,armature andi'ront contact of relay 31, I

scribed is completed whereupon the called,

subscriber is signalled.

When the relay 67 deenergizes at the close.

of the ringing-inteiwal, itcloses a circuit from ground at register. brush 36,.arinature and.

back :COlllZfiCt. of relay 67; armature; and. front.

1 finder brush 95,.rie'ht hand 80 deenergmenthe ringing circuit above de- L win dingot' relay 29,control switch brush 30 in position 8, winding of the resistance coilto grounded battery. Relay 29 is. thus energized andlocks l tSQlliJOPQlltItGCl..tl1I?Ollgll-ltS armature and tront Contact .tolground at control, brushlO.

:When relay 29 is actuated, it operates thev inotor. niagiietlB of the control switchto advanceit into position 15 in a circuitt'roni register. brush to position 15... The controller brushes of Fig. 1 remain. in positione i -thrush 10 to groundz The operation of the twoor more complete ,coderings, At the beginningof the. machine :ringing cycle the contacts .88 of the interrupter. are again .grounded battery,

and armature of. this motor. magnet, frontcontact and .ariiiature.:oi relay 29, control.

windin back contact .-i'ela y.29 also openstlie circuit of relay 25 causing it to release andin turn to effectthe closed to complete a ClICUlli fIOlfl ground;

conductor '89, unitsregistee brush 33 in posis tion 15, armature, back contact. .and'winding or" the magnet 32, to grounded ba-tterywhich circuit causes the unitsuregister. to .adyance its brushes into position 16.. The units.regis.-;

ter thenreniains in position 16 during a co1n-,. plete cycle of the COClQl'lIlglI-lg;1112lCh1I1BJl-ft6r.-.

which-the contacts 90 of the interrupter are closed to cause the motor magnet 32 to ad.. vance theunits register brushes into post.

tion 17 over a circuitcompletedover brusli33 in position 16. The release tone is now appl a m the;

register. finder, together with 'un' ts registers as. well.

.release of relay 3.1. The release of the relay '31 advances the units register to position .1

overfla cire iittraceable from grounded bat-e tei'y, winding, back contact and armature of iiiotor inagnet 32 units brush 33 in position 22, baclrcontact and armature of relay 31,

tens brush 42 in position 11 to ground. .The

the tons and as .the associated operating trunk c' cults are .now in normal condition.

In the foregoing description it was assumed that the called line was idle at the time that.

it Was tested. Let .it now be assumed that thecalled lineis busyand when the relay 65.

,upper winding and tlietest conductor 76 is open so that it deenergizes in the case of a call to a busy line before relay 69 deenergizes. Relay thus opens the circuit of relay 69 and the register sender completes its cycle of operations as above described in the case oi call to an idle line. In this case, however, relay 49 of the bridge circuit is not operated because the called line switch does not connect its finder to the selected bridge. VJ hen the control switch advances to position 15 it stops because there is no ground potential apolied at its brush 10 in position 15 to more its brushes past this position. A busy tone is no applied to the calling line trom the source BZ, condenser 96, brush 68 in position 15, armature and back contact 01 relay ($4 and thence over the upper side of the bridge and the upper side of the calling line to the calling substation. @311 receiving this busy tone the calling party replaces his receiver on its switchhook to effect the deenergiaation of the relays 11 and 12 which results in the restoration of the control switch to normal condition.

If the calling line is idle, the control switch will be advanced to position 15 as above dc scribed and since relay 49 is energized a cir cuit is closed from ground at controller brush 10 in position 15, lower armature and front contact of relay 49, arniiature, back contact and winding of the motor magnet 18 to grounded battery to advance the control switch to position 16 which is the talking position.

At thetermination oi h conversation the calling parry effects the lease of the connection by restoring his rec iver to its switchhook which ciiects the decnergization of the relays 11 and 12. This in turn restores the control switch to normal position from grounded battery, winding oi the magnet 13, its back Contact and armature, brush 20 in position to 22, back contact and armature of slow releasing relay 12 to ground.

In the event that the tens register is moved from its normal position accide. .l that is, when it is not being used in a call, provision has been made to restore it to its normal con dition. Under this assumption as soon as the tens register is moved from position 1, an operating circuit is closed for the motor magnet 38, cm grounded battery, its winding, Jack contact and armature, tens brush 3? in positions 2 and 3 to ground. This circuit advances the tens registo" into position 4. From this position the tens register is advanced to position 5 from grounded battery, winding of the motor magnet 38, its back contact and armature, brush 3? in posit on 4, back contacts and armatures of relays 31, 34 and 35 to ground. This ieg'ster i" tl vanced to position over circuit traceable from grounded battery, winding of the motor magnet 33, its back contact and armature, brush 37 in any of its p sitions 5 to 21 inelusive, back contacts and armatures ofrelays 34 and 35'to ground. This register is then restored to normal in a circuit completed from grounded battery, winding, back contact and armature oi the motor magnet 38,

units brush43 in position 1, tens brush 42 in position 22 to ground. It will be understood of course that it" the tens register has been a cidentally moved to any other position besides position 2 it will be restored to normal over the circuits just described.

Let it now be assumed that the units register is accidently moved from its normal position, for example into position 2. From this position the units register is advanced to position 3 over a. circuit extending from grounded battery, winding of the motor magnet 32, its back contact and armature, units brush 33 to ground. In position 3 of this register, there is completed an operating circuit for the tens register from grounded battery, win ing of the motor magnet 38, its back Contact and armature, tens brush 3? in position 1, units brush 36 in position 3. As soon as the tens register is moved from position 1 it advances into position 22 over the circuits previously described. The units register is new advanced to position 16 from grounded battery, winding, back contact and armature of the motor magnet 32, units brush 43 in positions 2 to 15 inclusive, tens brush 42 in position 22 to ground. When the contacts designated of the interrupter are closed, they complete a circuit from ground, units brush 33 in position 16, armature, backcontact and winding of the motor magnet 32 to grounded battery to advance the units register into position 17 where a circuit is completed for advancing this motor magnet into position 22 through units brush 43 over the circuit previously described as completed at tens brush 42 in position 22. With the units register in position 22 the tens register is advanced to position 1 over a circuit completed through units brush 43 in position 22 and tens brush 42 in position 22. The units register is now advanced to its normal position over a circuit from grounded battery, winding, back contact and armature of motor magnet 32, brush 33 in position 22, back contact and armature of relay 31, brush 42 in position 1 to ground.

Let it be assumed that the control switch of Fig. 1 is accidently advanced from position 1 in which case it will be restored to this position as follows. In position 2 of this switch a circuit is completed from grounded battery, winding, back contact and armature of the motor magnet 18, controller brush 20 in position 2, conductor 21, units brush 22 in position 1, winding of the slow releasing relay 23 to ground. This circuit energizes relay 23 to cause an idle sender to associate a register sender with the bridge related to thecontroller switch which is oil'- circuit from grounded battery, resistance,

lowermost contact and armature of relay 11,

brush 68 in position 3, back contacts and ar matures of relays 64, and a9, conductor 50, finder brush 51, tens brush 52, upper contacts of jack J, winding of drop 48 through the lower contacts of this jack, left hand wind ing of the impulse relay 35 to ground. This actuates the drop whereupon the'operator in;

serts the plug P into the jack J which causes the tens and units registers of the selector finder to advance as in the case'of a normal call. On discovering-that there is no call to be answered the operator removes the plug P from the jack J whereupon the tens and units registers are restored to their normal positions as already described. Vlnle the units register brush 36 is in any of its pos1- tions from 5 to 14 inclusive a circuit is closed from ground, through this brush, armature and back contact of relay 57 conductor 59, finder brush 60, conductor 61, control brush 20 in position 3, armature, back contact and winding of the motor magnet 18 to grounded battery. In position 4 the controller is advanced to normal from grounded battery, winding of the motor magnet 18, its back contact and armature, brush 20 in any of its positions 4 to 22 inclusive, back contact and armature of relay 12 to ground.

iVhat I claim is:

l. The method of extending telephone connections which comprises initiating the nonnumerical automatic extension of a calling subscriber to an operator by the use of alternating current control, informing the operator of the wanted subscribers designation, employing operator-transmitted code impulses corresponding to the wanted subscribers designation to automatically connect the called subscriber with the calling subscriber, and utilizing direct current control effected by the interruption of a portion of the conversational circuit between jthe called subscriber and the calling subscriber for releasing the connection.

2. The method of interconnecting the stations of subscribers located on party lines which comprises using code magneto current to signal a wanted subscriber in the case of a revertive call, employing magneto current in a difierent code to extend a calling subscriber to an operator, informing the operator of the designation of the wanted subscriber, employing direct current code impulses corresponding to the wanted subscribers designation to connect the wanted subscriber to the calling subscriber, and utilizing direct current control effected by the interruption of a portion of the conversational" "circuit betweentlie called subscriber flithe'balling subscriber for releasingthe "*connection. p p v 3.1Thef niethod of interconnectingthe stal tions of subscribers loc'atedonparty lines {which comprises using code magneto current magnate wanted subscriber in the'case of a revertive call, employing magneto current in a diiie'rent code to extend a callingsuh' sriber to an operator, informing the opera tor ofthe" designation of the wantedsubfpulses; corresponding to the wanted subscribersdesignation to connectth'e wanted subscriber to 'theicalling subscriberfautdmatically disconnecting the operator from the calling subscriber when the connection between'thc calling and the called subscribers has been completed, and utilizing'direct current control efiect'ed by the interruption offa portion of the conversational circuit between the called" subscriber and the calling subcriber for releasing the connection. 7

scriberswhic'h comprises automatically e):- tending a calling subscriber to an operator in response to 'codeinip ulses of magneto current, informing the operator of the wanted subscribers designation, employing code impulses corresponding to the wanted subscribers designation to set up a condition whereby the wanted subscriber is non-numerically, automatically connected to the calling subscriber, and utilizing direct current control effected by the interruption of a portion of the conversational circuit between the called subscriber and the calling sub-' scriber for releasing the connection.

5. In an automatic telephone system,local battery telephone party lines, a magneto generator for each party on a line for signal ling the other subscribers, a non-numerical switch for the use of each party line, bridge circuits multiply connected at each of their ends to said automatic switches, an operators position provided with an impulse transmitter, a register sender associated therewith, means including a non-numerical switch for connecting an 1dle register sender and operators position to a bridge'cir cuit taken for use, said register sender being adjusted in accordance with impulses corresponding to the designation of the wanted subscribers line transmitted from the operators impulse transmitter, means controlled by said adjusted register sender for causing the non-numerical switch of the wanted tele phone line to seize the bridge circuit which has been connected to the calling subscribers line, and means including a direct current circuit extending over a portion of a subscribers telephone line included in a telephone connection for releasing said connection.

6. In an automatic telephone system, a plusc'riber, employing direct current jcode imwi. The method of interconnecting subrality of local battery party telephone lines, a magneto for each party on a telephone line, an automatic non-numerical switch for each subscribers line, a plurality of link circuits,

each link circuit having an originating end and a terminating portion ending in said automatic switches, means controlled by the magneto of the calling subscriber on a line for causing its line switch to seize the originating end only or" a link circuit, an operators position, means for connecting said operators position to a bridge circuit that has been selected by a calling telephone line, and means controlled by impulses corresponding to a wanted subscribers line transmitted from said operators position to cause the automatic switch of a wanted subscribers line to seize the terminating portion of the selected bridge circuit, and means comprising a direct current circuit including a portion of the conversational circuit between the called subscriber and the calling subscriber for re leasing the connection.

In witness whereof, I, hereunto subscribe my name this 10th day of-October, A. D.

W'INFRED T. POWELL. 

